<template>
  <view>
    <view class="scroll-view-container">
      <!-- 左侧滑动区域 -->
      <scroll-view scroll-y="true" class="left-scroll-view" :style="{height:wh + 'px'}" >
        <block v-for="(item,i) in catelist" :key="i">
          <view :class="['left-scroll-view-item', i===active ? 'active':''] " @click="activeChange(i)" >{{item.cat_name}}</view>
        </block> 
       
      </scroll-view>
      <!-- 右侧滑动区域 -->
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px' }"  :scroll-top ="scrollTop" >
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
          <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
          <!-- 动态渲染三级分类的列表数据 -->
          <view class="cate-lv3-list">
            <!-- 三级分类 Item 项 -->
            <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodList(item3)" >
              <!-- 图片 -->
              <image   :src="item3.cat_icon" style="background-color: lightgoldenrodyellow;"></image>
              <!-- 文本 -->
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
      
    </view>
  </view>
</template>

<script>
  
  export default {
    
    data() {
      return {
        wh:0,
        catelist: [],
        active: 0,
        cateLevel2:[],
        scrollTop:0
      };
    },
    onLoad() {
      this.getCateList()
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight
    },
    methods:{
      
      async getCateList() {
        // 发起请求
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        // 判断是否获取失败
        if (res.meta.status !==200) return uni.$showMsg()
        // 转存数据
        this.catelist = res.message
        // 为二级列表赋值
        this.cateLevel2=res.message[0].children
      },
      activeChange(i){
        this.active =i
        // 为二级分类列表重新赋值
        this.cateLevel2=this.catelist[i].children
        
        this.scrollTop = this.scrollTop === 0 ? 1:0
        
      },
      gotoGoodList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+ item3.cat_id
        })
      }
      
      
      
    }
  }
</script>

<style lang="scss">
  
.scroll-view-container{
  display: flex;
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.left-scroll-view{
  width: 120px;
  .left-scroll-view-item{
    background-color: #f7f7f7;
    line-height: 60px;
    text-align: center;
    font-size: 12px;
    
    &.active{
      background-color: #fff;
      position: relative;
      
      &::before{
        content: ' ';
        display: block;
        width: 3px;
        height: 30px;
        background-color: #c00000;
        position: absolute;
        top: 50%;
        left: 0%;transform: translateY(-50%);
      }
    }

  }
  
}
.cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }

</style>
